Nanowire dimer optical antenna brightens the surface defects of silicon

Plasmonic hot spots located between metallic dimer nanostructures have been utilized comprehensively to achieve efficient light emission. However, different from the enhancement occurred in the plasmonic hot spot, the investigation of light emission off the hot spot on submicron scale remains challenge. In this work, we have constructed a plasmonic nanowire dimer (NWD) system to brighten the light emission of the surface defects of silicon off the hot spot on the submicron scale. The NWD can trap light through plasmonic gap, then, the excited emitter on the submicron scale can radiate light efficiently by coupling with the dipole gap plasmonic mode. Furthermore, the coupling of dipole plasmonic mode with the emitters can be tuned by changing the gap size, and then photoluminescence emission was drastically enhanced up to 126 folds. Theoretical simulations reveal the photoluminescence enhancement arises from the combination of the NWD’s high radiation efficiency, Purcell enhancement, efficient redirection of the emitted photoluminescence and the excitation enhancement. In this study, the photoluminescence signal can be effectively enhanced by placing nano-antenna patch on the detected low-quantum-efficiency emitters, which may open up a pathway toward controlling plasmonic gap mode enhanced light emission off the hot spot on submicron scale

Single-Mode Lasing with Spontaneous Symmetry Breaking from a Perovskite Microdisk Dimer

In this study, we design novel single-mode lasers based on non-Hermitian physics to avoid inadequate mode performance when the free spectral range is small. The perovskite microlaser, consisting of two partly fused microdisks, is presented here. Spontaneous symmetry breaking occurs under uniform pumping, which results in directional single-mode lasing at a visible range with an improved side-mode suppression ratio. In addition, a wide pump range becomes applicable due to microcavity property, where the single mode is stable even at 2.4 times the pumping threshold. The structural design with spontaneous symmetry breaking opens a new route to synthetic single-mode laser systems and other photonic devices at a visible range